Experimental Study of Discharge Process to an Open Wire and a Tree under Lightning Impulse Voltage

Abstract

For developing a rational lightning protection design of power distribution lines, we have investigated on sparkover characteristics when direct lightning hits on power distribution lines. In the previous study, lightning impulse voltages with negative polarity were applied to a rod electrode under the condition that an open wire of overhead distribution line was placed together with a tree. Then the rate of sparkover to an open wire and or to an open wire via a tree was examined.
In order to understand the phenomena, we made simultaneous observation of discharge development using an image converter camera and pre-discharge current. From the experimental result, the shielding effect of the tree near distribution lines is evaluated.